1 INTRODUCTION Palaeolithic rock art is one of the most relevant cultural phenomena in world history and, at the same time, one of the most fragile. Made with organic and mineral elements and carried out on the walls and ceilings of caves and shelters, as well as rocky outcrops, its conservation to date should be considered fortuitous, almost miraculous in some cases. Works done in natural pigments mixed with water and engravings carved onto a thin layer on the surface of the rock have been exposed for thousands of years to various natural and anthropogenic disturbances causing deterioration or disappearance. For this reason, rock art is an element of cultural heritage that needs special protection and special conservation measures. The main features that define the Palaeolithic cave art of the Cantabrian region, as well as the characteristics of this cultural manifestation in Cantabria, were reported by Gonzalez et al. (2003) and Ontañón (2009a). It should also be noted that Palaeolithic cave art is like no other, an important and distinctive element of the cultural heritage of Cantabria. Caves such as Altamira, Monte Castillo and La Garma are among the most remarkable Archaeological World Heritage sites and represent exceptional and universal values, as recently recognised by UNESCO (http://whc.unesco.org/en/list/ 310/) (Ontañón 2008, Ontañón 2009b,c) (Fig. 1). Rock art in Spain has sufficient legislative and institutional safeguards to ensure its preservation: It is endowed with the highest degree of protection recognised by the law at all levels of the Spanish administration: national, regional and local. The full and effective implementation of legislative and administrative measures should guarantee the protection of the properties against the dangers that threaten its conservation. These are due to natural causes and, in particular, factors related to human activity: construction of roads, pipelines, uncontrolled urbanisation, quarrying, mining and other operations as well as industrial facilities, uncontrolled garbage dumps and other forms of pollution underground. Here we will leave aside the different aspects of the protection of Cantabrian cave art considered from a legal and administrative perspective (ownership, legal status, application of the normative means) (Fernández, Lobo & Ontañón 2012) to focus on conservation issues. 2 ISSUES IN CANTABRIAN CAVE ART CONSERVATION There are many potential factors that could affect cave art sites and cavities which act as their support. They act in diverse ways in different areas and to varying degrees (Fortea 1993, Ontañón et al. 2011). These are summarised below. The conservation of prehistoric caves in Cantabria, Spain Roberto Ontañón Museo de Prehistoria y Arqueología de Cantabria - Cuevas Prehistóricas de Cantabria. Dirección Ge- neral de Cultura. Consejería de Educación, Cultura y Deporte. Gobierno de Cantabria Vicente Bayam & Jesús Herrera GIM Geomaticss Raúl Rodríguez Cuevas Prehistóricas de Cantabria. Dirección General de Cultura. Consejería de Educación, Cultura y Deporte. Gobierno de Cantabria ABSTRACT: Palaeolithic cave art is an important and distinctive element of the cultural heritage of Cantabria, Spain. In recent times the administration responsible of cave art conservation has directed its efforts to the development of a “Cave Art Management Plan”, promoted and conducted by the Cultural Heritage Department of the Directorate General of Culture from Cantabria in order to protect cave art.